Various freeze processes have been developed to produce potable water from seawater or brackish water; to concentrate fruit juices such as orange juice and grape juice, vegetable juices such as tomato juice, and coffee; and to separate dissolved or suspended salts from the liquid carrier. See, for example, the U.S. Pat. Nos. of Ashley et al 3,070,969; Ashley 3,477,241; Ashley 3,501,924, Ganiaris 3,620,034, Johnson 3,664,145 and Ogman 4,091,635.
One of the major problems in freeze concentrating a liquid mixture has been the deposition of frozen solvent, usually ice, on the freeze exchanger surfaces. Buildup of ice lowers heat transfer and reduces the efficiency of the apparatus. In addition, if buildup of ice or some other frozen solvent continues it can plug the apparatus completely making it necessary to shut down to thaw the frozen material. Accordingly, a need exists for more suitable apparatus for freeze concentrating liquid mixtures containing a dissolved or suspended solid material.